wintun: Simplify Read method()

Signed-off-by: Simon Rozman <simon@rozman.si>

diff --git a/tun/tun_windows.go b/tun/tun_windows.go
index 906a411cd80750646affae8fc34928faa043ca14..57be3dcccff55591be43bb39172d7a11efc3be2d 100644 (file)
--- a/tun/tun_windows.go
+++ b/tun/tun_windows.go
@@ -203,65 +203,65 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
        select {
        case err := <-tun.errors:
                return 0, err
-
        default:
-               for {
-                       if tun.rdNextPacket < tun.rdBuff.numPackets {
-                               // Get packet from the queue.
-                               tunPacket := &tun.rdBuff.packets[tun.rdNextPacket]
-                               tun.rdNextPacket++
-
-                               if packetSizeMax < tunPacket.size {
-                                       // Invalid packet size.
-                                       continue
-                               }
-
-                               // Copy data.
-                               copy(buff[offset:], tunPacket.data[:tunPacket.size])
-                               return int(tunPacket.size), nil
-                       }
+       }
 
-                       if tun.signals[signalDataAvail] == 0 {
-                               // Data pipe and interface data available event are not open (yet).
-                               err := tun.openTUN()
-                               if err != nil {
-                                       return 0, err
-                               }
-                       }
+       for {
+               if tun.rdNextPacket < tun.rdBuff.numPackets {
+                       // Get packet from the queue.
+                       tunPacket := &tun.rdBuff.packets[tun.rdNextPacket]
+                       tun.rdNextPacket++
 
-                       // Wait for user close or interface data.
-                       r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE)
-                       if err != nil {
-                               return 0, errors.New("Waiting for data failed: " + err.Error())
-                       }
-                       switch r {
-                       case windows.WAIT_OBJECT_0 + signalClose, windows.WAIT_ABANDONED + signalClose:
-                               return 0, errors.New("TUN closed")
-                       case windows.WAIT_OBJECT_0 + signalDataAvail:
-                               // Data is available.
-                       case windows.WAIT_ABANDONED + signalDataAvail:
-                               // TUN stopped. Reopen it.
-                               tun.closeTUN()
+                       if packetSizeMax < tunPacket.size {
+                               // Invalid packet size.
                                continue
-                       case windows.WAIT_TIMEOUT:
-                               // Congratulations, we reached infinity. Let's do it again! :)
-                               continue
-                       default:
-                               return 0, errors.New("unexpected result from WaitForMultipleObjects")
                        }
 
-                       // Fill queue.
-                       data := (*[exchangeBufferSize]byte)(unsafe.Pointer(&tun.rdBuff))
-                       n, err := tun.tunFile.Read(data[:])
-                       tun.rdNextPacket = 0
-                       if n != exchangeBufferSize || err != nil {
-                               // TUN interface stopped, returned incomplete data, etc.
-                               // Retry.
-                               tun.rdBuff.numPackets = 0
-                               tun.closeTUN()
-                               continue
+                       // Copy data.
+                       copy(buff[offset:], tunPacket.data[:tunPacket.size])
+                       return int(tunPacket.size), nil
+               }
+
+               if tun.signals[signalDataAvail] == 0 {
+                       // Data pipe and interface data available event are not open (yet).
+                       err := tun.openTUN()
+                       if err != nil {
+                               return 0, err
                        }
                }
+
+               // Wait for user close or interface data.
+               r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE)
+               if err != nil {
+                       return 0, errors.New("Waiting for data failed: " + err.Error())
+               }
+               switch r {
+               case windows.WAIT_OBJECT_0 + signalClose, windows.WAIT_ABANDONED + signalClose:
+                       return 0, errors.New("TUN closed")
+               case windows.WAIT_OBJECT_0 + signalDataAvail:
+                       // Data is available.
+               case windows.WAIT_ABANDONED + signalDataAvail:
+                       // TUN stopped. Reopen it.
+                       tun.closeTUN()
+                       continue
+               case windows.WAIT_TIMEOUT:
+                       // Congratulations, we reached infinity. Let's do it again! :)
+                       continue
+               default:
+                       return 0, errors.New("unexpected result from WaitForMultipleObjects")
+               }
+
+               // Fill queue.
+               data := (*[exchangeBufferSize]byte)(unsafe.Pointer(&tun.rdBuff))
+               n, err := tun.tunFile.Read(data[:])
+               tun.rdNextPacket = 0
+               if n != exchangeBufferSize || err != nil {
+                       // TUN interface stopped, returned incomplete data, etc.
+                       // Retry.
+                       tun.rdBuff.numPackets = 0
+                       tun.closeTUN()
+                       continue
+               }
        }
 }